题解 | #最小#
计算男生人数以及平均GPA
http://www.nowcoder.com/practice/7d9a7b2d6b4241dbb5e5066d7549ca01
-- select job|avg(1.0*score) from grade group by job ;
select job , round((1.0*sum(score)/count(id) ),3) as a from grade group by job order by a desc ;
